In the past few years, the Web has greatly facilitated the dissemination and sharing of GIS capabilities, leading to the new term Web GIS. This reflects the growing use of the Web as a platform that supports authoring geoprocessing models and maps, then publishing them as services that can be easily consumed by a variety of client applications. Ad hoc consumption of multiple data sources and distributed services makes it easier to find and use geographic information, as well as share it with other GIS professionals, customers, constituents, and the public.

Users can add their own GIS layers to Virtual Earth basemaps.

As an emerging dominant platform for both social and business-driven interaction, Web GIS merges (or mashes up) authoritative content with user-generated content to deliver location-based information and applications to a broader audience. Consumers can view a map showing the locations of gas stations with the lowest prices or analyze the impact a wildfire might have on their home and property. Emergency response officials can use that same wildfire map and add their own data on top of it to analyze how to plan and respond to a worst-case scenario, including routing personnel and equipment and devising evacuation routes for the populations at risk. Local governments can now provide information to their constituents in a more timely and cost-effective manner via the Web, allowing them, for example, to browse homeownership information or parcel records online or inform residents about upcoming street maintenance projects that will impact neighborhood traffic. Common to all these examples is the need for ready-to-use, current, and accurate basemap data that sometimes has to be available on short notice and onto which proprietary data can be easily overlaid, or mashed up, in order to provide information in a useful and meaningful context.

ArcGIS Online Services, powered by ArcGIS Server, can be crawled, indexed, searched, and used to share information and provide analytic capabilities to a broader audience over the Web or a network in the most effective manner. Developers who want to serve live, dynamic mapping applications over the Web can easily implement ArcGIS Online. For example, a viewer application, such as the one featured in the ArcGIS Online Services Resource Center (resources.esri.com/arcgisonlineservices) can be built quickly using the ArcGIS APIs for JavaScript. Users can also add additional content, such as photos or video and sound files.

In-depth description of the online map services, resolutions, coverage and podcasts on the next page…